Traction-engine



E. E. WICKERSHAM.

TRACTION ENGINE. APPLICATION FILED JAN. 18,1918.

1,356,679. N Patented Oct. 26, 1920.

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TRACTION ENGINE.

APPLICATION FILED JAN-18,1918

Patented 0013. 26, 1920.

4 SHEETS-SHEET 2 yo N RN A TTORNE Y5 E. E. WICKERSHAM.

TRACTION ENGINE.

APPLICATION FILED JAN. 18. 1918.

1 ,356,679, Patented Oct. 26, 1920.

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122226215 Wiefiens/zwa A TTORNE Y5 E. E. WICKERSHAM'.

TRACTION ENGINE.

APPLICATION FILED JAN-18,1918.

Patented 0015.26, 1920.

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ELMER E. WICKERSHAM, 0F STOCKTON, CALIFORNIA, ASSIGNOR TO THE HOLT MANU- FACTURING COMPANY, OF STOCKTON, CALIFORNIA, A

FORNIA.

CORPORATION OF CALI- TRACTION-ENGINE.

To all whom it may concern:

Be it known that I, ELMER E. WIOKER- SHAM, a citizen of the United States, residing at Stockton, in the county of San Joaquin and State of California, have invented new and useful Improvements in Traction-Engines, of which the following is a specification.

This invention relates to traction engines of the type in which the entire weight of the vehicle is supported upon a pair of endless, self-laying track mechanisms and in which steering is effected by varying the relative speed of said track mechanisms. It will be manifest that the invention is capable of wider application.

The chief object of the invention is the improvement in steering means which has heretofore generally been accomplished through the medium of friction clutches. In the present invention the steering is done through the medium of reduction gears of the planetary type located in the hub or hubs of the driving member or members and controlled by a band brake.

A further object involves the novel arrangement of parts whereby the usual tractor frame is eliminated, the truck frames of the self-laying track mechanisms being directly secured to the motor crank case and hollow extensions thereof, and

whereby the usual steering friction clutches are replaced by reduction gears carried within each drive sprocket. The tractor as a whole may thus be constructed with a minimum width equal to the sum of the widths of the two tracks and the motor crank case and yet beprovided with positive steering and driving gears of substantial dimensions for each track. The actuation of the track driving sprockets, by means of interiorly A preferred form of the invention is exemplified in the following description and Specification of Letters Patent- Application filed January 18, 1918.

Patented- Oct. 26, 1920.

Serial No. 212,383.

illustrated in the accompanying drawings, in which Figure 1 is a front elevation of a tractor embodying the invention, the links of the forward vertical run of the tracks being re moved.

Fig. 2 is a similar view of the rear end of the tractor, part of the housing being broken away to show the bevel gear and pinion.

Fig. 3 is a fragmentary detail elevation of the pivotal connection between the crank case and equalizer spring.

Fig. 4 is a similar view of the connection between the truckfraines and the ends of the equalizer spring.

Fig. 5 is a side elevation of the tractor,

dotted lines.

Fig. 6 is a plan view of one of the roller trucks.

Fig. 7 is a cross sectional view of the roller truck frame, taken on the line 77 of Fig. 5.

F Fig. 8 is a similar view on line 8-8 of *ig. 9 is a plan view of the tractor with the tracks removed.

Fig. 10 is an elevational, sectional view of one of the drive sprockets taken on line 10-10 of Fig. 11.

Fig. 11 is a cross-sectional View of the drive sprocket, taken on line 11-11. of Fig. 10.

As shown in the drawings, the particular embodiment of the invention described herein comprises a motor 12, preferably of the eight cylinder internal combustion type. The crank case 13 of motor 12 is provided with a hollow extension 14 at one end and a cylindrical boss 15 at the other, these memhers forming means to connect the motor to the self-laying track mechanisms in a manner to be described presently. It will thus be noted (see Fig. 9) that the tractor has not the usual main frame upon which the various mechanisms are supported and are secured. On the contrary. it. consists merely of a pair of self-laying track mech: anisms and a motor arranged between them in a manner to hold them in position and deliver power to them. The motor 12 is provided with a suitable radiator 16 carried on arms 17 secured to the motor.

The hollow extension 14 of the crank case 13 extends rearwardly and opens into a transversely disposed casing 19. The housing thus formed incloses change speed gears shown diagrammatically at 20, a propeller shaft 21 and a transverse driving shaft 22 carried in casing 19. Secured on either side of casing 14 are stub axles 23, fitted into bosses 24 on the casing 14. These axles 23 serve to support the rear end of the motor and connected mechanism on the roller truck frames 25. Suitable journal boxes 26 are carried on the rear ends of frames 25 for this purpose.

The front end of the motor is supported upon an equalizer bar, preferably consist ing of a semi-elliptical spring, such as that shown at 27. The spring 27 is pivotally secured at its center to the motor by means of shackles 28 having a yoke 29 engaging the boss 15 on the front end of the crank case 13. The outer ends of the spring 27 are fastened to the forward extremities of the frames 25 by means of clips 30. As shown in Fig. 4, these clips are preferably formed with inwardly curved dependent members 31 properly shaped to fit the forks of the truck frames.

The roller truck frames are struck out or punched from the blank stock in a manner to form one-piece frame members 25, having a U-shaped cross section. As shown in Fig. 7, the lower edges of the inverted channel member thus formed are turned outwardly forming flanges 32. The forward ends of frames 25 are forked, as shown in Fig. 6, the material from the central portion of the cross web of the channel member being formed into flanges 33, as shown in Fig. 8. A cross flange or strengthening rib 34 is formed on the upper side of the cross web of the channel member at the base of the forks, being in fact an upturned continuation of and connection between the flanges 33 (see Fig. 5).'

Carried on the forward end of the frames 25 and embracing the forks therein are yokes 35. These yokes are'provided at their outer ends with journal boxes 36, in which are mounted the axles of track carrying idler wheels 37. The yokes 35 are adjustably secured to the frames 25 by brackets 38 engaging the flanges 33, as shown in Fig. 1. and by adjusting screws 39 and brackets 40. By operating the screws 39 it is thus possible to-move the yokes backward or forward to regulate the tension of the endless tracks. The truck frames are .sup ')orted upon suitfable endless, self-laying tracksshown at 41,

means of a series of flangedirrollers 42 w fi ournaled between the depending sides of the channel shaped frames 25 on axles carliedin journal boxes 43 secured to flanges 32.

the means herein illustrated comprising rollclutch with a foot pedal 46 is interposed be- I tween the motor and the change speed gears and housed in the crank case 13. A suitable gear-shifting lever 47 is journaled in a cover plate 48 on the housing 14. The shaft 21 transmits power through bevel gearing 49 to the transverse driving shaft 22, which in turn drives the track-carrying and driving sprocket wheels 50, which are carried on the outer ends of said shaft.

Carried within sprocket wheels 50 and connected to the ends of drive shaft 22 are planetary gear mechanisms by which the relative speed of the drive sprockets may be varied. Since both of these mechanisms are alike the description will besimplified by explaining only one of them. Referring to Figs. 10 and 11 it will be seen that the sprocket wheel comprises an outer toothed rim 51, preferably of cast steel and formed with laterally extending flanges 52 by which By thus making the wearing portion of the" sprocket wheel removable it is possible to make it of high grade and expensive material without increasing the cost of manu-' facture. This construction also facilitates replacement of worn sprockets and decreases the cost of such replacements.

The outer end of the drum or hub 53 is preferably formed integrally with the cylindrical sides of said drum and provided with a central aperture in which is secured a journal box 54 fitted with roller bearings 55 to receive the ends of the drive shaft 22. The inner end of the drum is closed by means of a disk 56, having a flange 57 .at its outer edge by which it may be secured to the walls of the drum. A collar 58 formed about a. circular aperture atthe center of disk 56 serves as an inner bearing for the sprocket wheel as a whole. The interior of the collar 58 is provided with an oil retaining felt 'washer 59. The central drum or hub of the sprocket Wheel thus forms an oil and dust-proof case which may be partly filled with oil to lubricate the incased gears and bearings. v

Thehub 53 is driven by means of an a11- nular internal gear 60, secured interiorly thereof, and meshing witha set of'planetarygears 61, ournaled on roller-bearings 62 and pins 63 carried by arms'64 formed on a sleeve 65. This sleeve is journaledwithin and extends outwardly from the collar 58 and surrounds the shaft 22 upon which it is the rim may be secured in place upon a rotatably carried by means of roller bearings 66. The outer ends of pins 63 are secured in position by means of a circular plate 67 provided at spaced intervals with holes through which said pins are inserted, as shown in Fig. 10. Gears 61 are driven by a pinion 68 keyed on shaft 22 between the bearings 66 and 55.

Secured exteriorly of the hub 53, on the outer extension of the sleeve 65, is a brake drum 69. A brake band 70, arranged to engage said brake drum, is operated by means of a bell crank 71, link 72 and a hand lever 73. 74 is a spring seat for the driver and 7 5 is a draft yoke attached to the housing.

The steering of the machine is accomplished entirely through the medium of the planetary gears located in the hub and .contiolled by the brake 70. Normally in driving ahead the brakes are set so as to hold the brake drum 69, the sleeve 65 and the planetary gears 63 against rotation relative to the shaft 22. Slipping the brakes equally correspondingly varies' the speed; releasing one brake or slipping it and holding the other causes the machineto turn to the side on whichthe brake that has been slipped or released is located.

From the foregoing it is seen that controlling means are thus provided to vary the operation of the planetary gears in the well known manner and cause the sprockets to drive forward at various speeds. Since each drive sprocket is provided with a selfcontained reduction gear of this sort, it is obvious that each track may be positively driven forward-or reversed in unison or at different speeds by manipulating the hand levers 73 and gear shifting lever 47. By arranging the planetary gears within the drive sprocket the entire width of the tractor as a whole is greatly reduced Without necessitating any undesirable reduction in the size of the gears. Furthermore, this construction permits a very effective system of lubrication for the gears and eliminates the expensive steering friction clutches heretofore employed for steering tractors of this type.

It is obvious that various changes and variations 'could be made in the structure described herein without departing from the spirit of the invention as set forth in the appended claims.

Having thus described my invention, what I claim and desire to secureby Letters Patent is rear end of the motoron the track mechanisms. i

2. A tractor comprising a motor having a unitary crank case and a transmission housing, a self-laying track mechanism at each side of said motor, said track mechanisms having self-contained Speed-changing gears, an equalizer bar connecting the front end of said track mechanism and forming a central pivotal support for the front end of the crank case, and stub axles carried on either side of the transmission housing to connect the rear ends of the track mechanisms and support the motor thereon.

3. A self-laying track mechanism comprising an endless chain track, a truck frame having rollersengaging the ground run of the track, driving and carrying wheels about which the track travels, speed-changing gears carried interiorly of the driving wheel, and means whereby said wheel may be driven at various speeds. g

4. A self-laying track mechanism comprising an endless chain track, a truck frame having rollers engaging'the ground run of the track, driving and carrying wheels about which the track travels, planetary gears carried interiorly of the driving wheel, and a brake whereby said wheel may be driven at various speeds.

5. A tractor comprising a motor,'a selflaying track mechanism secured to either, side thereof, means to transmit power from said motor to the track mechanisms, said mechanisms comprising an endless chain track, a truck frame having rollers engaging the ground run of the track, driving and carrying wheels about which the track travels, and speed changing gears carried interiorly of the driving wheel whereby said whereby the operation of said gears may be varied to steer the traction engine.

7. In a traction engine having its entire weight supported upon a pair of self-laying tracks actuated by drive sprockets, the combination of means for steering the engine comprising planetary gears carried interiorly of each drive sprocket, and controlling brakes whereby the operation of said gears maybe varied to steer the traction engine.

8. In a traction engine having its entire weight supported upon a pair of self-laying tracks actuated by drive sprockets, the combination of means for steering the machine comprising drive sprockets having self-contained speed-changing mechanisms, and controlling means whereby the operation of said mechanisms may be varied to steer the traction engine.

9. A drive sprocket for self-laying track tractors comprising a drum, a drive shaft rotatab'ly journaled in said drum, a toothed rim carried exteriorly of the drum, an internal gear carried interiorly of said drum, and controllable planetary gearing interposed between the drive shaft and the internal l0 ear. g 10. The combination with the drive shaft of a selflaying track tractor, of a drive sprocket having a toothed rim provided with an internal gear, planetary gears connecting the drive shaft and the internal gear, and means to control the planetary gears to drive, the sprocket at varying speeds.

11. A variable speed drive sprocket for self-laying track tractors comprising an oil tight drum, a drive shaft on which said drum is journaled, and gearing within said drum whereby said shaft may drive the drum at various speeds.

12. A variable. speed drive sprocket .for self-laying track tractors comprising an oil tight drum rotatably mounted on a drive shaft, a toothed rim carried on the outside of the drum, an internal gear carried interiorly thereof, a sleeve rotatably carried on the drive shaft and extending into the drum, and planetary gears carried by said sleeve and meshing with the internal gear on the interior of the drum and a pinion gear on the drive shaft.

13. A variable speed .drive sprocket for self-laying track tractors comprising an oil tight drum rotatably mounted on a drive shaft, a toothed rim carried on the outside of the drum, an internal gear carried interiorly thereof, a sleeve rotatably carried on the drive shaft and extending into the drum, planetary gears carried by said sleeve and meshing with the internal gear on the interior of the drum, a pinion gear on the drive shaft, and a brake. drum carried by said sleeve and provided with a brake band whereby the operation of the planetary gears may be controlled.

14:. A tractor comprising a motor, a selflaying track mechanism secured to each side of said motor, and means to drive said ea ers sprockets comprising an oil tight drum, a

toothed rim carried exteriorly andan internal gear carried interiorly thereof, .a

sleeve rotatably carried on the drive shaft and extending into said drum, and planetary gears carried by saidsleeve and meshing with said internal gear and a pinion on the drive shaft.

16. A tractor comprising a motor, a pair of self-laying track mechanisms, and means to secure said mechanisms to the motor, said means including supports carried on. either side of the motor, and resilient means to support the front end of the motor upon and midway between the track mechanisms.

17.. A tractor comprising a motor, a pair of self-laying track mechanisms, means to secure said mechanisms to the motor, said means including stub axles to support one end of the motor upon the track mechanisms, and an equalizer spring extending from one track mechanism to the other and provided with a central pivotal support for the front end of, the motor.

18. The combination of a driving sprocket containing a hollow hub, reduction gears of the planetary type in the hollow hub, and a brake for controlling the planetary gears,

19. The combination of a driving sprocket containing a hollow hub, reduction gears of the planetary type in the hollow hub, a brake for controlling the planetary gears, and means for entirely housing in the gears in the hub against the ingress of dirt.

20. The combination of a drive shaft, a planetary gear set thereon, a sprocket with an internal gear meshing with the planetary gears, said sprocket mounted for independent rotation on the drive shaft, a brake drum rotating with the planetary gears, and a brake band operative on the brake drum.

21. In a traction engine, the combination of a pair of endless, self-laying tracks laying side by side and spaced from each other, roller trucks within the self-laying tracks, load supporting means bearing upon the trucks and comprising a combined engine and transmission case with the forward end of the same supported by an equalizing bar 011 the forward ends of the trucks, and outriggers atthe rear end of the transmission case bearing on the rear end of the trucks and on which outriggers the trucks pivot.

22. In} a chain track tractor, a motor, a propeller shaft operatively connected with the motor, a housing for the propeller shaft also connected with the motor at one end, an axle operatively connected with the propeller shaft and extending transversely thereof, a housing for the axle connected with the housing for the propeller shaft,

a'sprocket Wheel carried at each end of the the main frame of the tractor, the whole axle for driving a chain track, a roller truck being supported upon the truck mechanisms mechanism for each chain track, a bracket at three points. extending outwardly at either side of the In testimony whereof I have hereunto set 15 fipropeller shaft housing and connected with my hand in the presence of two subscribing the alolljacent 1truci: mechanism for supportd: witnesses. 7 ing 1; e weig t o the tractor thereon, an 1 T 1 I an equalizer bar extending between opposite Y ELMLR 'WIQKERSHAM' truck mechanism and on which the motor Witnesses:

10 is pivotally supported, said motor, pro- C. L. NEUMILLER. peller shaft, and axle housing constituting DAVID B. LYMAN. 

